Heat treating furnace



F. T. COPE HEAT TREATING FURNACE Re.l8,668

Nov. 29, 1932.

Original Filed Oct. 5, 1929 Suva/valor Fran/i [b oe Reissuecl Nov. 29, 1932 UNITED; STATES K T. COPE, 0F SALEM, OHIO, ASSIGNOR TO THE ELECTRIC FURNACE COMPANY, OF

PATENT oF lc I SALEM, OHIO, A CORPORATION OF OHIO HEAT 'rpEA'rING FURNACE Original No. 1,794,151, dated February 2 1, 1931, Serial no.

397,017, filed October 3, 1929. Application for reissue filed December 1'7, 1931. Serial No. 581,764.

I The invention relatesto heat treating furnaces of that type in whichthe work to be heated is supported in a hollow or tubular mass within the furnace, hot air being circulated within the hollow mass of work and then outward through the same.-

.An object of the improvement is to provide a furnace chamber having heating means at its sides, and a bafile wall spaced from the heating means and from the top and bottom of the chamber, means being provided for supporting a hollow or tubular mass of work inside of the baffle walls, and means, such as a fan, being provided for circulating air between the heating means and bailie walls, then into the interior of the hollow or tubular mass of work and then outward through the work, this circulation of air being preferably continuous. 4

Another object of the improvement is to providea furnace especially adapted for the' heat treatment of small articles which are placed in the furnace in a container or receptacle sealed at both ends, a baffle wall being located-between the heating means and the container, and a perforate pressure chamber being located within the receptacle and provided with a fan or-the like for continually forcing heated air through the container, the air within the furnace chamber as it is cooled passing downward past the heating means where it is reheated and again circulated upward through thecontainer.

An embodiment of the invention is illustrated in the accompanying drawing, in which The figure is a vertical sectional view; through a furnace constructedin accordance with the invention.

Similar numerals refer to similar parts throughout the drawing.

The furnace maybe of any usual and well known construction, comprising the side walls 10 and bottom wall 11 formed of suitable refractory material and enclosed in the metallic shell 12, the entire structure being preferably supported spacedabove the floor 13 as by the channel irons 14.

The furnace is preferably provided with a removable roof or crown 16 of suitable refractory material enclosed in the metal shellor frame 17 and preferably provided with the depending flange 18-for normal entrance into the sand sealing'channel 19 carried at the upper open end of the furnace proper.

For the purpose of easily removing and replacing the roof or crown, a vertical post 20 may be supported at one side of the furnace and have mounted thereon the sliding bracket 21 provided with the horizontal arm 22 connected to the central portion of the roof frame or shell.

r A weighted lever 23 may be provided for counterbalancing the weight of the roof when the same is raised and moved from overthe furnace chamber.

Any suitable heating means, such as the electric resistors 24, may be provided around the inner walls of the furnace chamber or elsewhere in the path": of the fluid, as will be later described. Bafiie walls 25 are located within the furnace chamber and spaced a slight distance from the heatin'g'elements.

These baffle walls terminate at their upper ends near the upper end of the furnacejchamher, the lower ends thereof being extended toward the center of the furnace as at 26 and terminating in a hollow frustum 27.

A. fan 28 is located at the base of the frustum, being mounted on the vertical shaft 29 jcurnaled through a suitable bearing 30, 111 the bottom wall of the furnace, and driven, by any suitable means, such as the motor 31 ghich may be located within a pit 32 in the cor.

The container or basket, which receives the articles to be heat treated, is adapted to be placed within the baflie walls 25 and rest upon the horizontal portions 26 thereof and is indicated generally M133, being preferably provided at its lower end with the. de ending flanges or fins 34 for contact upon t e horizontal walls 26. q

This container is preferably provided with the central pressurephamber 35 which may be slightly coned at itb. lower end as at 36,

whereby the container may be easily centered upper end of the tube being closed as by the wall 38 and a removable cover 39 being pro- Vided for closing the body portion of the container.

In operating the furnace, the'articles to be heat treated are placed within the container 33 and the roof of the furnace is then raised and moved to one side, permitting the con tainer to be lowered into place as shown in the drawing.- a

The roof is then replaced upon" the furnace and the fan 28 operated, circulating the air in the direction of the arrows'shown in the drawing, the hot air passing upward through the frustum 27 and into the pressure chamber 35, passing through the openings therein and through the container and then out through the openings of the container and upward over the baille wall 25.

As the air cools it descends past the heating elements 24 where it is reheated and again circulated through the pressure chamber and container. It will be seen that this tends to maintain an even temperature in the articles in all parts of the container, thus giving each article substantially the same heat treatment as all of the other articles in the furnace.

This device also conserves the heat as the heated air is continually being drawn away from the heating elements and forced directly onto the articles to be treated.

I claim:

1. A furnace including a chamber, heatin means at the sides of the chamber, baflie walls spaced from the heating means and from the bottom of the chamber, and terminating near the top of the chamber, a basket provided with perforated side walls for holding material within the bafiie walls, and means for circulating air upward into the basket and out through the perforated side walls and downward between the heating means and baflie walls.

2. A furnace including a chamber, heating means at the sides of the chamber, baffle walls spaced from the heating means and from the I bottom of the chamber, and terminating near the top of the chamber, a basket provided with perforated side walls for holding material within the bafile walls, and a fan in the chamber for circulating air-upward into the basket and out through the perforated side walls and downward between the heating means and baflle walls.

3. A furnace including a chamber, heating means at the sides of the chamber, bafile walls spaced from the heating means and from the bottom of the chamber, and terminating near the top of the chamber, a basket provided with perforated side walls for holding material within the battle walls, and a fan in the bottom of the chamber for circulating air upward into the basket and out through the perforated side walls and downward between the heating means and baflle walls.

4. A furnace including a chamber, heating means at the sides of the chamber, baflle walls spaced from the heating means and from the bottom of the chamber and extending in wardly adjacent the bottom of the chamber, and terminating near the topof the chamber, a hollow frustum at the inner termination of the baflie walls,a perforate basket for holding material within the baffle walls, said basket having a ccntral,'perforate pressure chamber adapted to register with said hollow frustum, a cover for the top of the basket, and means for circulating air upward through the hollow frustum and pressure chamber, through the basket, and downward between the heating means and battle walls.

5. A furnace including a chamber, heating means at the sides of the chamber, bafile walls spaced from the heating means and from the bottom of the chamber and. extending inwardly adjacent the bottom of the chamber, and terminating near the top of the chamber, a hollow frustum at the inner termination of the heme walls, a perforate basket for holding material within the baflle walls, said basket having a central, perforate pressure chamber adapted to register with said hollow frustum, a cover for the top of the basket, and a fan at the bottom of the hollow frustum for circulating air upward through the ber, through the basket, and downward beg tween the heating means and baflle walls'.

6. A furnace including a heating chamber, baffle walls spaced from the side walls of the heating chamber and from the top and bottom of the chamber, a material receptacle having a perforate outer wall spaced from the baffle walls, a pressure chamber within the receptacle and having a perforate wall, the top and bottom of the receptacle being sealed whereby fluid from the pressure cham ber must pass through the material in the receptacle, heating means located in the path of the fluid, and means for circulating air upward through the pressure chamber.

7. A furnace including a chamber, heating means at the sides of the chamber, bafiie Walls a cover for the top of the basket, and means for circulating air upward through the air inlet, outward through the perforate pressure chamber into and through the basket, outward through the perforated side walls of the basket, and downward between the 1 heating means and battle walls.

8. A furnace including a chamber, heating means at the sides of the chamber, baflle walls spaced from the heating means and from the top and bottom of the chamber, means for sup ortin work in the chamber within the ba e wall s, there being a central chamber defined by said work supporting means, and

means for forcing a current of air to flow from behind the baffle walls into said central chamber and. for causing said current of air to escape from the central chamber through the work.

9. A furnace including a chamber, heating means at the sides of the chamber, bafile walls spaced from the heating means and from the bottom of the chamber. and terminating near the top of the chamber, means for supporting a tubular mass of work within the afiie walls, means for circulating air within said tubular mass of work, and closure means at the ends of the tubular mass of work for causin said air to escape laterally out throug the work and between the heating means and baflle walls.

10. A furnace including a chamber, heating means at the sides of the chamber, baflle walls spaced fromthe heating means and from the bottom of the chamber and terminating near the top of the chamber, means for sup orting a tubular mass of work within the bathe walls, means for circulating air upward Within said tubular mass of work, and closure means at the ends of the tubular mass of work for causing said air to escape laterally out through the work, and downward between the heating means and battle walls. V

11. A furnace including a chamber, heating means at the sides of the chamber, bafile walls spaced from the heating means and from the top and bottom of the chamber, means for supporting a tubular mass of work within the baflie walls, a perforate tubular wall within the tubular mass of material, and

means for circulating air within said perforate wall and laterally out through the material and between the heating means and bafflewalls.

12. A furnace including a chamber, heating means at the sides of the chamber, baflle walls spaced from the heating means and from the top and bottom of the chamber, means for supporting work in the chamber Within the baflie walls, a central chamber within the work, means for forcing a current of air to flow behind the said baflles into one end of said central chamber, a closure for the opposite end of the central chamber, and a closure for the upper end of the work whereby said air current is caused to escape laterally from the central chamber through the work.

' FRANK T. CORE.- 

